This
is a multisystem connective tissue
disease characterised by the presence of numerous autoantibodies,
circulating immune complexes, activation of complement and widespread
immunologically mediated tissue damage. SLE affects individuals throughout the
world but occurs more frequently in the United States (especially Blacks) and
the Far East. The onset is most commonly in the 2nd and 3rd decades, with a female
to male ratio of 9:1, the prevalence of SLE is around 1:2,500.

Although
the cause of SLE remains obscure, several factors may be involved.

1.It appears that genetic factors
are important in the aetiology of the disease because of frequent occurrence
in identical twins, and higher than expected prevalence of SLE, other
autoimmune connective tissue diseases, antinuclear antibodies and immune
complexes in related family members.

2.Certain environmental factors
have been also implicated in pathogenesis of SLE because it has been reported
that exposure to sunlight can
exacerbate the disease (but probably not cause it), as well as several drugs (especially anti-epileptic diphenylhydantoin, anti-arrhythmic procainamide, vasodilator hydralazine
and anti-tuberculotic isoniazid). Exacerbations of SLE commonly occur in pregnancy
and after delivery, and become infrequent in menopause; also prevalence is
increased in women who have several children and those using oral
contraceptives, suggesting the possible role of oestrogens.

3.All available evidence suggests that SLE in an autoimmune condition, as
many immunological abnormalities are
detectable in the blood of patients with SLE:

Circulating
immune complexes which are frequently deposited in many tissues initiating
inflammatory reactions

Immunologically-mediated tissue damage results
from at least two different mechanisms:

Direct Type II antibody-mediated cytotoxicity
with activation of complement may be responsible for brain damage and
miscarriage (cytotoxic effect of antibodies which cross-react with fetal
tissues and neurons) as well as haemolytic anaemia, leukopenia and
thrombocytopenia.

Immune complex mediated Type III hypersensitivity
also known as immune complex disease can explain the mechanism of renal and
vascular lesions, which appear to be a consequence of deposition of
circulating DNA-anti-DNA and other complexes in tissues with subsequent acute
inflammation; vasculitis is thought to underlie probably most of the
tissue/organ damage.

These are the commonest presenting features
and occur in more than 90% of

patients and the
joints commonly involved are the proximal interphalangeal,metacarpophalangeal, wrist and knees (differential diagnosis with
rheumatoid arthritis is essential).

Symptoms may begin during pregnancy and there
may be a past history of

spontaneous
miscarriages.

The arthritis can be transient and migratory
or a more persistent polyarthritis.

In contrast to rheumatoid arthritis lupus
polyarthritis is usually non-destructive and non-deforming (no actual damage
of the joint cartilage).

Skin/mucosal
lesions

They are seen in more than two-thirds of
patients, usually in form of erythematous ‘butterfly?/i>
rash across the face(involving the bridge of the nose and malar areas of the face) and
macular reddish-purple lesions on the palms, fingers, arms and trunk.

Other skin lesions such as widespread rash
due to minute skin bleeding (purpura),

may appear
secondary to thrombocytopenia or vasculitis (inflammation in the blood vessel
wall with subsequent vessel rupture).

Alopecia
(hair loss) is seen in more than 50% of patients during active phases of SLE
but it is generally reversible.

Painful
oral ulcers.

Cardiopulmonary
features

These include pericarditis with retrosternal
chest pain, myocarditis and endocarditis (may produce increased heart rate
and fatigue or heart murmurs), pleurisy with pleuritic pain, fibrosing
alveolitis with thickening and hardening of alveolar walls.

SLE
diagnosis is largely clinical and according to American Rheumatism Association
at least four of the following eight symptoms must occur, either serially or
at the same time before a diagnosis can be made:

The ESR
is usually raised in active disease (interestingly C reactive protein can be
very low), while haematological findings may include normocytic normochromic
anaemia of chronic disease, sometimes autoimmune haemolytic anaemia,
leukopenia, thrombocytopenia.

Immunological
findings are essential for diagnosis and include

Antinuclear antibodies (ANA) can be detected
by indirect immuno-fluorescence in the serum of more than 90% of patients but
positive tests are found in many other autoimmune conditions.

Anti-DNA antibodies detected by ELISA
(enzyme-linked immunosorbent assay) technique have much greater specificity,
but are present in the serum in only half the patients. Other autoantibodies
mentioned earlier can also be identified in some but not all patients.

An evidence for circulating immune complexes
may be obtained by using special techniques.

Tissue evidence for immune complex deposition
comes from detection of immunoglobulins by direct immunofluorescence in skin
or organ biopsies.

Main
treatment is with corticosteroids (e.g., prednisolone [Delta-Cortef,
Panafcortelone, Solone]) which can be given initially in large doses.

With
remission of disease careful attempts are made to withdraw steroids or
maintain patients on very low doses.

NSAIDs
may be used for symptomatic relief of articular symptoms.

Immunosuppressive
drugs (e.g., azathioprine [Imuran, Thioprine] or cyclophosphamide [Cycloblastin,
Endoxan]) are reserved for patients with severe diffuse progressive
glomerulonephritis who are not responding adequately to corticosteroids.

Plasma
exchange can be attempted when, using the equipment similar to haemodialysis
machine, patient’s plasma can be separated and replaced by fresh plasma
(patient’s plasma is then discarded together with autoantibodies and immune
complexes).

This condition is more common than SLE and it primarily effects the skin. The
main feature is sharply circumscribed round macules and plaques showing
erythema, scaling, telangiectasis (visible dilated blood vessels) and in time
atrophy. These skin lesions are characteristically sensitive to sunlight, and
therefore they tend to appear more frequently on light-exposed areas of the
skin (face, ears, upper trunk and extensor surfaces of the extremities).
Involvement of the scalp may lead to hair loss (alopecia) that can be
permanent. Some patients develop mild systemic features, and a few them may
end up later with SLE.
It is advised that patients avoid unnecessary exposure to sun and wear sunscreens whenever going outside.
Skin lesions are treated with topical corticosteroid creams, but avoiding
their excessive use.